The nucleotide sequence of the 5' flanking region of the Arabidopsis ACS2 gene

The ACS2 gene of Arabidopsis thaliana encodes 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (EC 4.1.1.14) - the key regulatory enzyme in the biosynthetic pathway of the plant hormone ethylene. The gene is unique among ACC synthase genes isolated thus far in that it is highly expressed in both reproductive (e.g. flower) and vegetative tissues (e.g. leaves and roots). In addition, the accumulation of ACS2 transcripts is greatly induced by protein synthesis inhibition (Liang et al 1992). We report here the DNA sequence of the 5' flanking region of the ACS2 gene and an analysis of the sequence with respect to the potential cis-acting regulatory elements that can be recognized by DNA-binding proteins from plants and other organisms.

The 1-aminocyclopropane-1-carboxylate synthase gene family of Arabidopsis thaliana

Genomic sequences encoding five divergent 1-aminocyclopropane-1-carboxylic acid (ACC) synthase polypeptides (ACC1, ACC2, ACC3, ACC4, and ACC5) have been isolated from Arabidopsis thaliana by using heterologous cDNAs and PCR fragments amplified from genomic DNA with degenerate oligonucleotide primers. Each gene is located on a different chromosome in the Arabidopsis genome. The genes are differentially expressed during development and in response to environmental stimuli. Protein-synthesis inhibition derepresses the expression of all genes but most dramatically derepresses that of ACC2, suggesting that their expression may be under negative control. The sequence of ACC2 was determined, and its transcription initiation site was defined. Authenticity of the polypeptide encoded by the gene was confirmed by expression experiments in Escherichia coli. The predicted size of the protein is 55,623 Da, and it contains the 11 invariant amino acid residues conserved between aminotransferases and ACC synthases from various plant species. Comparative analysis of structural and expression characteristics of ACC synthase genes from Arabidopsis and other plant species suggests that the sequence divergence of the ACC synthase genes and possibly the distinct regulatory networks governing the expression of ACC synthase subfamilies arose early in plant evolution and before the divergence of monocots and dicots.

Modification of fruit ripening by suppressing gene expression

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An in vivo study of a glycoprotein gIII-negative bovine herpesvirus 1 (BHV-1) mutant expressing beta-galactosidase: evaluation of the role of gIII in virus infectivity and its use as a vector for mucosal immunization

We constructed a recombinant BHV-1 in which the glycoprotein gIII gene was replaced by the Escherichia coli lacZ gene. The resultant virus mimics the simple gIII deletion mutant in its growth characteristics in cell culture; however, it expresses beta-galactosidase in virus-infected cells. Further characterization of its virulence and the immune responses elicited by it was conducted in cattle. The mutant virus retained the ability to establish an infection when administered intranasally. Infected animals were also capable of transmitting virus to sentinel penmates. However, the mutant virus showed a reduced replication efficiency in the respiratory tract of cattle, as manifested by significantly lower virus shedding and a shorter duration of shedding when compared to wild-type (wt) BHV-1 infections. The mutant virus induced an efficient anti-BHV-1 antibody response and convalescent cattle were fully protected from subsequent wt virus challenge. In addition, cattle infected with the lacZ-expressing virus developed antibodies to beta-galactosidase. Our results demonstrate that the presence of gIII is not a prerequisite for BHV-1 infection; however, gIII does play an important role in maintaining virus replication efficacy in its natural host. With respect to developing BHV-1 as a vaccine vector, our results indicate that deletion of the gIII gene, which partially attenuates the virus and serves as a vaccine virus marker, does not compromise immunogenicity to BHV-1. Most importantly, this vector is effective in delivering foreign antigens to mucosal surfaces of the respiratory tract.

cis-element combinations determine phenylalanine ammonia-lyase gene tissue-specific expression patterns

The bean phenylalanine ammonia-lyase gene 2 (PAL2) is expressed in the early stages of vascular development at the inception of xylem differentiation, associated with the synthesis of lignin precursors. This is part of a complex program of developmental expression regulating the synthesis of functionally diverse phenylpropanoid natural products. Analysis of the expression of PAL2 promoter-beta-glucuronidase gene fusions in transgenic tobacco plants showed that functionally redundant cis elements located between nucleotides -289 and -74 relative to the transcription start site were essential for xylem expression, but were not involved in expression in leaf primordia and stem nodes or in establishing tissue specificity in petals. The -135 to -119 region implicated in xylem expression contains a negative element that suppresses the activity of a cryptic cis element for phloem expression located between -480 and -289. The functional properties of each vascular element are conserved in stem, petiole, and root, even though the xylem and phloem are organized in different patterns in these organs. We conclude that the PAL2 promoter has a modular organization and that tissue-specific expression in the vascular system involves a negative combinatorial interaction, modulation of which may provide a flexible mechanism for modification of tissue specificity.

Detection of HPV-16 DNA in cervical carcinoma by paraffin section in situ hybridization

Thirty-eight cervical carcinomas and one cervical condyloma were examined for the presence of human papillomavirus type 16 (HPV-16) DNA using 3H-dcTP-labelled HPV-16 DNA probe in paraffin section in situ hybridization and dot blot hybridization (Tm-17 degrees C). The results showed that HPV-16 DNA positive rate in our series was about 74.4% (29/39) as determined by paraffin section in situ hybridization and about 71.8% (28/29) by dot blot hybridization. There was no significant difference between the two methods. We thus confirmed that paraffin section in situ hybridization is an informative, reliable, and sensitive method for the diagnosis of cervical HPV infection.

The association between cervical carcinoma and human papilloma virus (HPV) in Xiangyuan County

A mass survey was conducted to investigate the association between cervical carcinoma and human papilloma virus (HPV) infection in a high-risk area, Xiangyuan County, Shanxi Province. Fifty-four cases of cervical cancer in situ (CIS), including severe dysplasia (CIN III), 14 cases of invasive cervical carcinoma, 28 cases of mild cervical dysplasia (CIN I), and 13 cases of moderate cervical dysplasia (CIN II) were identified among 6710 women examined. One hundred and sixty-nine punch biopsies from abnormal cervix and genital tract were examined for the presence of HPV 6B/11, 16 and 18 DNA sequences by dot blot hybridization: The positive rates of HPV infection in cervicitis, CIN I, II, III, CIS and invasive cervical carcinoma specimens were 35.06% (27/77), 25% (2/8), 33.33% (2/6), 40% (2/5), 70.58% (24/34) and 40% (4/10), respectively. Among these groups, there was no regular distribution of HPV types except for HPV 16, the positive rate of which was increased from 25% in CIN I to 46.15% in CIS: HPV 16 was also the only type seen in the invasive cervical cancer group. Distribution analysis of HPV types in HPV-positive cervical cancer tissues uncovered an HPV 16 positive rate of 59.4%; 3.7 and 2.4 times higher than those of HPV 6B/11 and HPV 18, respectively. These data confirm the close association between cervical cancer and HPV 16 infection.

[Isolation of bilirubin oxidase from Myrothecium verrucaria and the optimum conditions of enzyme production]

A bilirubin oxidase (EC 1.3.3.5) producing strain, Mv 2.1089, was isolated from several strains of Myrothecium verrucaria by dilution method. The optimum conditions of enzyme production were investigated and the results were as follows: the suitable medium was cultured at 25 degrees C on a rotating shaker glucose and peptone, at pH 6.0. The strain was cultured at 25 degrees C on a rotating shaker (150 r/min) for 96 h. Bilirubin oxidase with 0.5-1.5 u/ml was obtained in the culture medium.

[Obliterative peripheral retinal vascular disease in children]

Obliterative peripheral retinal vascular disease in children is a rare disease. Only 4 cases had been reported abroad. No case of this disease was reported in China before. This paper reported a 13-year-old girl suffering from this disease in both eyes. Neovascular glaucoma of her left eye has developed and that of her right eye was still in early stage. Fluorescein angiography changes, diagnosis and differential diagnosis, pathogenesis and treatment of the disease were discussed.

Effects of trans-Cinnamic Acid on Expression of the Bean Phenylalanine Ammonia-Lyase Gene Family

Using DNA probes specific for the three members of the bean (Phaseolus vulgaris L.) phenylalanine ammonia-lyase (PAL) gene family, we have studied the effects of the product of the PAL reaction, trans-cinnamic acid (CA), on the appearance of individual PAL transcripts in suspension cultured bean cells. Concentrations of CA in excess of 10(-4) molar inhibited appearance of elicitor-induced transcripts encoding PAL1, PAL2, and PAL3 when added to the cells at the same time as fungal elicitor. Addition of CA 4 hours postelicitation caused a major reduction in the levels of all three PAL transcripts, but with different kinetics and subsequent rates of recovery. The inhibition of accumulation of PAL1, PAL2, or PAL3 transcripts, measured 3 hours after exposure to elicitor, as a function of the time of addition of CA postelicitation reflected the different rates of appearance of the three PAL transcripts in the presence of elicitor alone. The inhibitory effects of CA as seen on PAL transcripts were not observed for the constitutively expressed transcript H1, or the elicitor-inducible 1,3-beta-D-glucanase. Analysis of in vitro translated polypeptides showed that some elicitor-induced mRNA activities were not down-regulated by CA, and that a number of other mRNA activities were induced by CA, thus providing further evidence for specificity in the action of CA on bean cells. Treatment of elicited cells with L-alpha-aminooxy-beta-phenylpropionic acid, a potent and specific inhibitor of PAL activity, resulted in maintenance of elevated PAL transcript levels beyond 12 hours postelicitation, this effect being greatest for PAL transcripts 2 and 3. Our results are consistent with a model in which CA, or a derivative, could act as a component in a regulatory feedback system operating at the level of phenylpropanoid gene transcription.

Variability in the functional activity of vaccine-induced antibody to Haemophilus influenzae type b

Sera from 3 of 30 adults vaccinated with Haemophilus influenzae type b polysaccharide vaccine (Hib PS) had poor complement-mediated bacterial activity despite the presence of anti-Hib PS antibody concentrations of 8.6 to 20.5 micrograms/mL. These "nonkiller" antibodies killed less than 0.4 log cfu/mL compared to greater than 3 logs with all but one of the other sera. To investigate the basis of this poor functional activity, we characterized in detail the IgG antibodies to Hib PS present in two of the nonkiller sera, and compared the results with two of the "killer" sera. The latter were selected based on comparable levels of total antibody to Hib PS. No consistent differences were found between the relative proportions of IgG or IgA antibody to total anti-Hib PS antibody, or the respective ratios of IgG1 to IgG2 antibody in the nonkiller and killer sera. IgG fractions, and IgG affinity purified antibody to Hib PS were prepared. When tested at 2 micrograms/mL of antibody, the IgG fractions from the two nonkiller sera had much lower bactericidal activity than the corresponding fractions from the killer sera (3 logs less killing), and the former also had lower complement-mediated opsonic activity (20 and 13% uptake by human PMN compared to 62 and 93%). These data show the striking variability in the functional activity of vaccine-induced antibody to Hib PS. Antibody functional activity is likely to be affected by a number of factors but one important variable appears to be avidity since the IgG anti-Hib PS antibody from the two nonkiller sera had 2- to 5-fold lower avidity than the IgG antibody from the two killer sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental factors and Parkinson's disease: a case-control study in China

We studied the role of environment in the development of Parkinson's disease (PD) in China, where industrialization is relatively recent and the population geographically stable. Using a case-control method, we investigated the relationship between PD and exposure to the following factors before disease onset: place of residence, source of drinking water, environmental and occupational exposure to various agricultural and industrial processes. Occupational or residential exposure to industrial chemicals, printing plants, or quarries was associated with an increased risk of developing PD. In contrast, living in villages and exposure to the common accompaniments of village life, wheat growing and pig raising, were associated with a decreased risk for PD. PD cases and controls did not differ with respect to other factors investigated. These findings are consistent with the hypothesis that environmental exposure to certain industrial chemicals may be related to the development of PD.

Phenylalanine ammonia-lyase gene organization and structure

Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) genomic sequences were isolated from bean (Phaseolus vulgaris L.) genomic libraries using elicitor-induced bean PAL cDNA sequences as a probe. Southern blot hybridization of genomic DNA fragments revealed three divergent classes of PAL genes in the bean genome. Polymorphic forms were observed within each class. The nucleotide sequences of two PAL genes, gPAL2 (class II) and gPAL3 (class III), were determined. gPAL2 contains an open reading frame encoding a polypeptide of 712 amino acids, interrupted by a 1720 bp intron in the codon for amino acid 130. gPAL3 encodes a polypeptide of 710 amino acids showing 72% similarity with that encoded by gPAL2, and contains a 447 bp intron at the same location. At the nucleotide level, gPAL2 and gPAL3 show 59% sequence similarity in exon I, 74% similarity in exon II, and extensive sequence divergence in the intron, 5' and 3' flanking regions. S1 nuclease protection identified transcription start sites of gPAL2 and gPAL3 respectively 99 bp and 35 bp upstream from the initiation codon ATG, and showed that gPAL2 but not gPAL3 was activated by elicitor, whereas both were activated by wounding of hypocotyls. The 5' flanking region of both genes contain TATA and CAAT boxes, and sequences resembling the SV40 enhancer core. gPAL2 contains a 40 bp palindromic sequence and a 22 bp motif that are also found at similar positions relative to the TATA box in 5' flanking regions of other elicitor-induced bean genes.

Uniform illumination of large targets using a lens array

Inserting an array of nearly 100 similar lenses into a common focal system, the uniformity of the illumination of a target can evidently be improved without being affected by the near-field distribution of laser beams. We report here geometrical- and physical-optics analyses of the lens array and compare them with the experimental results.